It has been well known to provide rifles or pistols with sights to guide the operator in aiming the firearms. High power scopes are often utilized to provide an accurate sight at most ranges. The scope is mounted on the top of the firearm to provide a magnified view of the potential target when sighted. Cross hairs within the scope are used to sight the target, with the intersection of the cross hairs being placed exactly on the intended target. Limitations of the high powered scope include the problem that the scope must be “calibrated” to assure accuracy. Typically, adjusting screws are provided which can be used to adjust the scope so that the cross hairs are accurately marking the target. If a rifle, for example, was mounted on a stand and the target sighted in the cross hairs of the scope, minor adjustments of the scope may be necessary to assure accuracy. Adjustments are made by firing a round of ammunition and noting where the round strikes with respect to the target. Mechanical adjustment of the scope can then be made to align the cross hairs of the scope with the actual point at which the round of ammunition struck the target. It may take several attempts of this trail and error firing of the rifle and adjusting the scope to bring the cross hairs in line with the actual striking point of the ammunition round. As can be expected, this procedure, even when performed by a skilled marksman, is time consuming and inherently imprecise.
Designers have adapted lasers to aid in the sighting process of a firearm. Some lasers have been designed to be mounted to the top of the barrel. However, oftentimes the path of the ammunition round does not follow the exact path of the laser's light. As such, even when one finally aligns the scope with the laser beam the scope is still misalinged with the round's path. To alleviate this problem, lasers have been designed to be mounted within the barrel of a rifle to more accurately depict the path of the round. Some of these lasers have been positioned within the end of the barrel. These lasers however do not always align with the ammunition's path of travel. To provide more accuracy, lasers have been designed to include a housing configured to be mounted within the breech or chamber of the barrel. With the laser positioned within this area the light from the laser generally follows the bore of the barrel and thus the path of the ammunition. Of course, the laser diode within the housing may have to be adjusted so that the light does indeed travel along the bore of the barrel.
A problem with these devices has been their ability to incorporate an on/off or activation switch. The front end of such laser bore sight must include the laser diode, which obviously can not be obstructed by a switch. The side walls of the laser bore sights are designed to rest within the same sized bore of the gun barrel or breach. As such, the side housing can not include a switch which would interfere with the proper seating of the laser bore sight within the rifle bore.
Some laser bore sights having included a switch at the rear end of the sight which is activated by the hammer or firing pin of the gun pressing upon a switch, as shown in U.S. Pat. Nos. 5,365,669 and 5,787,631. A problem associated with this type of switch is that the operator may be under the false impression that the laser is not activate when in reality it is activated by the pressing of the firing pin. This results in the laser not being deactivated and therefore continuing to operate until the battery is exhausted. Moreover, the harsh hitting of the hammer or firing pin upon the switch may cause damage to the switch or laser diode as a result of the impact or resulting vibration.
Laser bore sights have also been developed wherein the activation of the sight is caused by the positioning of the bore sight within the bore. Here, the metal housing of the laser bore sight contacts the metal barrel of the gun while a second portion of the laser bore sight contacts another metal portion of the gun in order to close the power circuit, i.e. the gun itself creates a conductive pathway or bridge which closes the power circuit so as to activate the laser diode. This concept is shown in U.S. Pat. No. 5,465,669. However, once again, the operator may be under the impression that the laser is only activated when the sighting process is underway, and may not realize that the laser is still activated afterwards. Also, here again, a portion of the switch contacts the hammer or firing pin of the gun, which may cause damage to the delicate components of a laser.
Accordingly, it is seen that a need remains for a laser bore sight which is not automatically turned on when it is placed within a gun and which does not include a switch that will be activated by the striking hammer or firing pin of a gun. It is to the provision of such therefore that the present invention is primarily directed.